GENERAL DESCRIPTION
The bowhead whale is an Arctic baleen whale, a right whale with a large, bow-shaped head that is up to 40% of its body length. The arched mouth is up to 10 feet (3 m) wide and 20 feet (6 m) deep. The eyes are very small and lips are huge. Bowheads live in pods, are rich in blubber (a subcutaneous layer 20-inch (50 cm) thick in places), and have 2 blowholes.

SIZE
Bowhead whales grow to be about 50-60 feet (15-18.5 m) long, weighing over 80-110 tons (72-91 tonnes). The females are slightly larger than males, as with all baleen whales.

SKIN, SHAPE, AND FINS
The bowhead whale's skin is usually black with a white spot on the lower snout. Calves are blue to gray colored.

Bowheads have no dorsal fin and no throat grooves. They have short, narrow flippers; the flukes are 27 feet (8.1 m) wide.

DIET AND BALEEN
Bowhead whales (like all baleen whales) are seasonal feeders and carnivores that filter feed plankton and tiny crustaceans like krill, copepods, pteropods, etc., from the water. Bowheads are skimmers, filter feeders that swim slowly with their mouth open, constantly eating. On occasion, they are also bottom feeders, eating benthic prey from the mud on the ocean floor. The fine baleen hairs can filter out very tiny prey including copepods, steropods, euphasids and mysids (tiny crustaceans).

The bowhead whale has about 350 pairs of black baleen plates with silver-colored bristles hanging from the jaws. The baleen is the longest of any whale and very fine; baleen plates are about 175.5 inches (4.5 m) long and 14 inches (36 cm) wide

SOCIAL GROUPS
Bowhead whales are not extremely social and congregate in small pods of about 3 whales in the spring and pods of about 50 whales in the fall.

DIVING
Bowhead whales can dive for almost an hour, but dives usually last 4-15 minutes. They can go to a depth of 500 feet (155 m).

SPOUTING - BREATHING Bowhead whales breathe air at the surface of the water through 2 blowholes located near the top of the head. They spout (breathe) about 1-2 times per minute at rest, and 4-6 times per minutes to prepare for a dive. Their blow is bushy and rises in two cloudy masses 20 feet (6 m) above the surface of the water. Bowheads can break through surface ice (less than 1 foot or 0.3 m thick) in order to breathe. They may use echolocation to determine the thickness of the ice.

SPEED
Bowhead whales normally swim (cruising or migrating) at 2-7 mph, but can go up to 10-12 mph (16-19.5 kph) in short bursts when in danger. Feeding speeds are slower, about 1.2-2.5 mph (1.9-3.2 kph).

VOCALIZATION
Bowhead whales vocalize when on migrations, mostly between the frequencies of 50-300 Hertz. The songs may be used for locating large masses of krill (tiny crustaceans that they eat) and for communicating with other whales.

HABITAT
Bowhead whales live exclusively in the Arctic at the surface of the ocean.

MIGRATION
Bowhead whales stay in arctic waters, making a northern migration in the spring to rich feeding waters. They migrate south again in the fall to breed and calve. Migrating speeds range from 2-7 mph (3.2-11 kph).

REPRODUCTION
The bowhead gestation period is about 12-16 months and the calf is born tail first (this is normal for cetaceans) and near the surface. The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped by its mother, using her flippers. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 17 feet long and weighs about 5-6 tons (4.5-5.4 tonnes). Twins are rare; there is usually one calf. The baby is nurtured with its mother's milk and is weaned in about 1 year. The mother and calf may stay together for a year or longer. Bowhead whales reach puberty at 6 years.

LIFE SPAN
Bowhead whales have a life expectancy of at least 40 years, but perhaps longer.

POPULATION COUNT
It is estimated that there are about 8,000-12,000 bowhead whales world-wide. Bowhead whales are an endangered species.

CLASSIFICATION
Bowhead whales (Balaena mysticetus) are baleen whales (Suborder Mysticeti). They are one of 76 cetacean species, and are marine mammals.